Looks like it is time for round two... So for any of you who were following my other post (https://www.physicsforums.com/showthread.php?t=762560) about whether or not to glue my model or make a solid piece for a modal analysis, you know that I was having a lot of trouble deciding. It turns out that the decision was made by my overseeing professor who said he wants a solid piece. Easy peasy right? WRONG!!!! Well turns out that it is not that easy because my mentor now wants to weld the piece instead. So now what I am looking for is some suggestions on whether or not to go with my mentors idea of welding it or to suggest that we do the solid milled piece. I know that there are some issues that come along with aluminum welding, though I am unsure of what they actually are, that could make the process a little difficult. And to those of you just joining in, the problem is that I am creating a model out of aluminum that has unit cell dimensions of 6x6x6 cm for the main structure and then a pillar on top (non load bearing) that is 1.5x1.5x3 cm. these will be lined up in a long rod with the pillars on one side of the rod. the rod will be about 90 cm in length. I am performing a Modal Analysis of this structure in the frequency range of 10-8000 Hz and need to know (now) if welding the structure would be a viable solution to our problem or if we should go with the solid piece. Based off of the last discussion; I am still feeling solid piece, but it is not up to me. So I am looking for some solid reasoning, for or against welding or solid structure. Or if you have any other ideas that could be viable (unfortunately this does not include shrink fitting due to our shop moving) Thanks!